Computer Aided Design (CAD) applications are used to produce computer models of two and three dimensional objects as part of a production process for a physical device that is being modeled. The models frequently include multiple part bodies which must be individually designed. A part body is a computational model used by a CAD application to hold a solid or a sheet (open body with zero thickness) geometry. Once the designer is satisfied with the design, an actual physical device may be produced using the CAD model.
3D scanning captures physical geometry information for a three-dimensional object by gathering high resolution points representing the shape of the scanned three-dimensional object. The 3D scan data can be represented by either a set of points or dense triangular (or other shaped) meshes which cumulatively form a model of the scanned object. The model can be segmented into multiple groups referred to as regions. In a mesh model, the region is a mesh region that is a set of triangular facets which can be arbitrarily defined by the user or can be automatically identified by a computer program. The computer program can also be designed to detect and group planar, cylindrical, spherical, conical, toroidal, or freeform mesh regions by estimating and tracing the curvature information. Once captured, the raw 3D scan data may be converted to a CAD part model for further processing to replicate or modify the design of the three-dimensional object. This procedure of capturing 3D scan data for a three-dimensional object in order to provide it to a CAD application so that the object may be replicated or redesigned is referred as reverse engineering.
Remodeling a 3D CAD part body using 3D scan data requires time-consuming tasks. One of the complexities comes from the fact that a part body can only be operated on by other part bodies. For instance, a user can use a Boolean operation to merge two part bodies but conventionally there is no way to merge a CAD part body and a 3D scan data model. The user is forced to design a CAD solid or sheet bodies which replicate a scan data region as an intermediate step before the user can proceed to further regular CAD modeling procedures.